[5] The decay of the Sultanate of Rum brought unexpected instability to the Anatolian frontier, as nobles known as ghazis began setting up fiefdoms at the expense of the Byzantine Empire.

To solve these problems, Michael VIII began consolidating his rule; he had the younger co-emperor John IV blinded, which resulted in much resentment.

The death of the old Byzantine Emperor came as a relief for the society at large; his policy of Latin appeasement to the Church in Rome, heavy taxation and military expenditure placed a severe burden on the people.

As the Ottoman Turks began taking land from the Empire, they were seen as liberators of Anatolians and many soon converted to Islam undermining the Byzantine's Orthodox power base.

To popularize his rule he repudiated the union of the Orthodox and Catholic Churches decreed by the Second Council of Lyon in 1274, thereby further increasing hostilities between the Latins and the Byzantines.

[12] Andronikos II took a deep interest in preserving the Anatolian lands of Byzantium and ordered construction of forts in Asia Minor and vigorous training of the army.

[12] The Byzantine Emperor ordered that his court be moved to Anatolia to oversee the campaigns there and instructed his General Alexios Philanthropenos to push back the Turks.

Under the guidance of Michael IX and the leadership of Roger de Flor, the 6,500-strong Catalan Company in the spring and summer of 1303 managed to drive back the Turks.

The mercenaries' onslaught drove the Turks back from Philadelphia to Cyzicus, in the process causing great destruction to the Anatolian landscape.

When they finally left in 1307 to attack Byzantine Thrace, the locals welcomed the Ottomans who once again began blockading key fortresses in Asia Minor.

Throughout the civil war the Byzantines on both sides employed Turks and Serbs with mercenaries pillaging at will,[19] leaving much of Macedonia in ruin and in the hands of the newly created Serbian Empire.

However, just like Alp Arslan of the Seljuk Turks, Murad I left the taking of Byzantine territory to his vassals with Philippopolis falling after major campaigning between 1363–64 and Adrianople succumbing to the Ottomans in 1369.

The Ottomans continued their thrust into the Balkans, proving to be great conquerors in Europe as they were in Anatolia; in 1385 Sofia was captured from the Bulgarians[5][25] and Niš was taken the following year.

Ottoman advances into the Balkans were aided by further Byzantine civil conflict – this time between John V and his eldest son Andronikos IV.

The siege was finally broken when Timur of the Chagatai Mongols led an army into Anatolia, dismantling the network of beyliks loyal to the Ottoman Sultan.

[33] The rare amity established between the two states would not last; the death of Mehmed I and the rise of Murad II in 1421 coupled with the ascent of John VIII to the Byzantine throne led to a deteriorated change in relations between the two.

John VIII made the first and foolish move by inciting a rebellion in the Ottoman Empire: a certain Mustafa had been released by the Byzantines and claimed that he was Bayezid's lost son.

Despite a union of the Catholic and Orthodox Churches, the Byzantines received no official aid from the Pope or Western Europe, with the exception of a few soldiers from Venice and Genoa.

The Venetians considered sending their fleet up to attack the fortifications guarding the Dardanelles and the Bosporus, thereby relieving the city, but the force was too small and arrived too late.

[citation needed] The fall of Constantinople came about due to the combined weight of overwhelming odds stacked against the city – outnumbered by more than ten to one, the defenders were overcome by sheer attrition as well as the skill of the Ottoman Janissaries.

[citation needed] In an effort to raise morale, the Sultan then made a speech[39] reminding his troops of the vast wealth and pillaging of the city to come.

The blood flowed in the city like rainwater after a sudden storm, and the corpses of Turks and Christians were thrown into the Dardanelles, where they floated out to sea like melons along a canal.After the siege, the Ottomans went on to take Morea in 1460, and Trebizond in 1461.

[41] With the fall of Trebizond came the end of the Roman Empire; the Palaiologoi continued to be recognized as the rightful emperors of Constantinople by the crowned heads of Europe until the 16th century when the Reformation, the Ottoman threat to Europe and decreased interest in crusading forced European powers to recognize the Ottoman Empire as masters of Anatolia and the Levant.

Byzantine rule in its former sphere ended fully following the conquests of several major rump states: the Fall of Trebizond in 1461, Theodoro in 1475, and Epirus (then under the Tocco family) in 1479.

This is exemplified by Michael VIII Palaiologos, whose attempts to drive the Latins out of Greece led to the abandonment of the Anatolian borders which allowed several beyliks, as well as the Turks of Osman I to raid and settle former Byzantine lands.

This is in contrast to the civil strife of Byzantium, occurring at a time (1341–1371) when the Ottomans were crossing into Europe through a devastated Gallipoli and surrounding the city, thus sealing its fate as a vassal.

In time however, as the Turks began to settle in land formerly held by the overextended Byzantines,[44] they were able to exploit the hardships of the peasant classes by recruiting their aid.

[46] The failed attempts at defeating the Ottomans at Nicopolis and Varna, the loss of the Holy Land (without Byzantium the Crusades could not re-supply en route) and the lack of a genuine counter-attack led many, including Martin Luther, into believing that the Turks were God's punishment against the sins of Christians: How shamefully ... the pope has this long time baited us with the war against the Turks, taken our money, destroyed so many Christians and made so much mischief!

Martin Luther, changing his views, wrote that the "Scourge of God"[47] had to be fought with great vigour by secular leaders rather than as Crusades initiated by the papacy.

Their success through the Janissaries became their new weakness; due to their conservativism and power, Ottoman reform was difficult to implement whilst European armies became increasingly more resourceful and modernized.